Reversible pulsator domes for fuel pumps



Dec. 21, 1965 w. J. i-ucKs REVERSIBLE PULSATOR DOMES FOR FUEL PUMPS Filed June 5, 1965 f0 II 11/ 22 2Q J i" #0 J6- p J8 i v I M T as a: :z L- 7' ,7 Q: /6 ll 11/ Di 24 /0 4a INVENTOR.

WM. J. HICKS United States Patent 3,224,377 REVERSIBLE PULSATOR DOMES FOR FUEL PUMPS William J. Hicks, Fairfield, llL, assignor to Airtex Products, Division of United Industrial Syndicate, Inc., New York, N.Y., a corporation of New York Filed June 3, 1963, Ser. No. 285,113 9 Claims. (Cl. 103-150) The present application relates to fuel pumps, and more particularly to pumps of the type having air compression chambers wherein the air is compressed and rarified alternately as the diaphragm is actuated. Such chambers are called pulsator domes and are required for the dual purpose of smoothing out flow, particularly in the pump outlet and also for the very important purpose of providing a compression chamber in the outlet side of the pump so that the spring of the pump, which actuates the diaphragm on the force stroke, can expand without being blocked by a solidly filled fuel line to the carburetor bowl. One of the problems in connection with fuel pumps for use in motor vehicles is the number of different models that have to be made to fit into specific car models. In particular, certain car models provide spaces for a fuel pump which must be inverted in order to fit into the allotted space, whereas other car models are installed in upright position.

The present invention overcomes the need for differently designed fuel pump models, depending on whether the pump is to be installed upright or in inverted position. Thus, fuel pumps designed for normal operation in upright position do not function properly when inverted and this is due to reduction of the pulsator dome effectiveness when the air trapped in the dome by the pumped fuel cannot be properly compressed or might subsequently bubble out of the compressed region.

Accordingly, it is a primary object of the present invention to provide a fuel pump construction which may be used in either upright or inverted position, and wherein .a manufacturing economy is thus effected by the use of the same pump for either type of installation.

Other objects and features of the invention will be apparent from the description that follows.

Briefly, the invention contemplates the use of separate and reversible pulsator air domes. Thus, in the course of assembly, such pumps which are intended for upright use are assembled with the air domes in upright position, whereas such pumps which are intended for inverted installation are assembled with the air domes likewise in upright position but in inverted position relative to the pump structure. By making the air domes of stamped sheet metal having force fit within chambers of the pump casting, a very economical structure is achieved, as well as simple assembly.

A detailed description of the invention now follows, in conjunction with the appended drawing, in which:

FIG. 1 is an elevational cross section through the essential components of a fuel pump utilizing the invention;

FIG. 2 is an elevational cross section through the essential components of FIG. 1 in inverted position;

FIG. 3 is an enlarged perspective of a pulsator dome as used in the invention;

FIG. 4 is a plan view of the exterior of the pump, although showing a difierent angularity of arrangement of the inlet and outlet ports as compared with FIG. 1, and being partially broken away and sectioned to show details.

Referring now to the drawing, the invention comprises cast body members such as 10 and 15 having clamping flanges of conventional construction, as shown, and clamping a flexible diaphragm 17 therebetween in the usual manner, facing valved passages in separate chambers. The body member 15 supports the usual pump actuating elements, such as the stem 20 which pulls the diaphragm downwardly on an intake stroke and the spring 24 which pushes the diaphragm in the reverse direction for the discharge stroke, all in a well known manner. Thus, the diaphragm is clamped between plates 27 and 30 and flexes with each cycle of operation. In the body member 10 is a conventional inlet check valve 33 and a conventional outlet check valve 36, each in its own separate valve chamber.

The member 10 is open at one end and is divided into a pair of merging cylindrical chambers 38 and 40 for inlet and outlet, respectively, of fuel. Chamber 38 communicates via an inlet port 43 to a source of fuel (not shown) and chamber 40 communicates via an outlet port 46 to the carburetor bowl (not shown). Any conventional holding structure for the valves may be used, or the valves may be understood to be secured by force fit at predetermined locations in the respective chambers.

Thus, the body member 10 comprises, geometrically, two intersecting cylinders with a wall 50 therebetween, there being communication between the two cylinders via the diaphragm or pump chamber 52 so that fluid brought in by suction via inlet port 43 can pass valve 33 as the diaphragm moves downwardly, as viewed in FIG. 1, and be forced upwardly to outlet port 46 when spring 24 pushes the diaphragm upwardly. The pumping action described is generally conventional.

The crux of the invention resides in the separate pulsator chambers or air domes 55 which are identical and, as shown in FIG. 3, each comprises an open ended cylinder or casing having a plurality of hollow radial ridges 58 pressed outwardly from the open end and extending longitudinally toward the closed end a substantial portion of the length of the cylinder. cylinder 55 can be pressed into the respective body chamber and pushed to a predetermined location relative the valve, being retained by friction-a1 force fit. Locations relative to the valve may be different for each valve chamber although critical placement in each chamber is not necessary. However, an advantage of the invention as to versatility of air dome placement will be apparent, and this may be of advantage in certain kinds of cars, i.e., the ability to vary the individual location of the air domes for optimum efliciency in a particular speed range or in conjunction with particular pump cams which actuate the pump lever or with regard to kind of fuel used.

The orientation for a pump to be installed upright is as shown in FIG. 1, and it will be apparent that fuel drawn in from inlet port 43 can pass between the exterior surface of cylinder 55 and the interior surface of the valve chamber 38 to reach valve 33. Similarly, fuel forced past valve 36 can pass around the cylinder 55 in the valve chamber 40 to reach outlet port 46. However, in the action of the pump, a certain amount of air is trapped in the upper volume of each of the pulsator domes and is retained there by fuel filling the open bottom of the domes and extending upwardly therein and thus acting to compress the trapped air within the domes. Accordingly, such a pump may be installed in upright position and will operate in the same manner as any other type of pulsator dome fuel pump.

The particular feature of the invention in addition to the simplification of body casting effected by the assembly thus described, is illustrated in FIG. 2, wherein it will be .noted that the pump is shown in inverted position, al-

though the pulsator domes 55 are still upright so that .the open bottoms face downwardly. In other words,

when it is desired to supply fuel pumps for car models which require inverted installation, assembly of such pumps is made selective as to orientation of the air domes 55 which are in upright position precisely as in FIG. 1,

It will be apparent that a although actually reversed relative to the housing member 10. The same pulsator action and trapped air compressibility is effected thereby.

From the above description, it will be apparent that selective assembly is provided by virtue of the use of individual and separate air domes for either upright or inverted pumps. Viewing the air domes as shown in FIG. 1 it will be noted that air will be trapped in the upper closed portion of the inlet chamber dome as the fuel from inlet port 43 comes in around the sides of the dome, passing through the longitudinal valleys provided by the ridges 58 and up into the dome. On the outlet side of the pump, as shown in FIG. 1, it will be obvious that fuel will pass upwardly through valve 36 and thence into the dome in the outlet chamber to effect trapping and compression of air. The outlet flow of fuel passes the sides of the dome by virtue of the ridges 58, to outlet port 46.

In FIG. 2, the inverted position, it will be apparent that fuel from inlet port 43 can readily pass the dome 55 and move through inlet valve 33, a certain portion of the fuel rising into the dome to trap and compress air therein; on the outlet side the fuel downwardly around the sides of the dome and a certain amount of its moves upwardly into the dome trapping and compressing air therein.

I claim:

1. A fuel pump comprising a body member having an inlet and an outlet chamber, a valve in each of said chambers, ports in said chambers at points spaced from respective valves and an air dome member in at least one of said chambers intermediate the respective port and the respective valve, said air dome member being secured in said chamber and means whereby said member is spaced radially from walls of said chamber to permit fuel to flow to the respective valve between said walls and said member.

2. A fuel pump comprising a body member having an inlet and an outlet chamber, a valve in each of said chambers, ports in said chambers at points spaced from respective valves and an air dome member in at least one of said chambers intermediate the respective port and the respective valve, said air dome member being secured in said chamber and means whereby said member is spaced radially from walls of said chamber to permit fuel to flow between said walls and said member, said air dome member comprising a substantially cylindrical housing, said means frictionally engaging said walls of said chamber for retaining said air dome member in said chamber.

3. A fuel pump comprising a body member having an inlet and an outlet chamber, a valve in each of said chambers, ports in said chambers at points spaced from respective valves and an air dome member in at least one of said chambers intermediate the respective port and the respective valve, said air dome member being secured in said chamber and means whereby said member is spaced radially from walls of said chamber to permit fuel to flow between said walls and said member, said air dome member being a substantially cylindrical container, said chamber in which said air dome is disposed having a substantially cylindrical interior wall, said means comprising similarly spaced radially extending elements frictionally engaging said wall for retention of said air dome member in said chamber.

4. The combination of a fuel pump comprising a body member having an outlet chamber and an air dome reversibly insertible in said chamber, said air dome being a container having a closed end and an open end and having a transverse dimension matching the chamber dimension so as to be inserted and secured therein with the open end of said air dome selectively facing either end of said chamber.

5. A fuel pump comprising a body member having an outlet chamber and an air dome reversibly insertible in said chamber, said air dome being a container having a closed end and an open end and having a transverse dimension matching the chamber dimension so as to be inserted and secured therein with the open end of Said air dome selectively facing either end of said chamber, said air dome being provided with exterior fuel passages so that fuel can move between said air dome and the walls of said chamber with a certain portion of fuel moving into said air dome to trap and compress air therein.

6. A reversible position fuel pump comprising, in combination, a first pump body having a pair of axially parallel tubular passages and being substantially closed except for an open end communicating with said tubular passages, a flexible pumping diaphragm closing said open end, a second pump body substantially enclosing said flexible diaphragm and means extending into said second body for actuating said diaphragm, each of said tubular passages having a check valve secured therein and each of said passages having a port axially spaced from the respective check valve and each of said passages having a hollow pulsator element therein, each of said pulsator elements being formed with protuberances frictionally engaging walls of respective passages for holding said pulsator elements therein in selective positions, the spacing between protuberances affording flow channels for fluid to flow between each port and its respective valve.

7. A fuel pump comprising a body member having an open end and having inlet and outlet chambers, a pumping diaphragm at said open end, said chambers communicating with said open end, an air dome in at least one of said chambers, said air dome being a separate member having an interior substantially closed to permit air to be held therein and having an open end for providing access of air to said interior and being disposed in said chamber for air entry, said member having exterior structure fitting in said chamber, and of conforming shape so as to be positionable therein with its open end selectively facing the open end of said body member or facing in the opposite direction, dependent on whether said fuel pump is mounted for operation with the open end of said body member facing upwardly or downwardly, whereby said air dome is effective to hold air in either position of said fuel pump body member.

8. A fuel pump as set forth. in claim 7, said air dome member being substantially cylindrical and said exterior structure having raised portions extending radially and engageable with Walls of said chamber in either of said positions to effect spacing for fuel fiow between said air dome member and said walls.

9. A fuel pump comprising a body member having an inlet and an outlet chamber, a valve in each of said chambers, ports in said chambers at points spaced from respective valves and an air dome member having a closed end and an open end in at least one of said chambers intermediate the respective port and the respective valve, said air dome member being secured in said chamber and means whereby said member is spaced radially from walls of said chamber to permit fuel to flow to the respective valve between said walls and said member.

References Cited by the Examiner UNITED STATES PATENTS 2,025,232 12/1935 Dodge. 3,096,721 7/1963 White et al 103-224 X 3,096,722 7/1963 Fitzgerald et al. 103-224 X DONLEY J. STOCKING, Primary Examiner.

WARREN E. COLEMAN, LAURENCE V. EFNER, Examiners. 

1. A FUEL PUMP COMPRISING A BODY MEMBER HAVING AN INLET AND AN OUTLET CHAMBER, A VALVE IN EACH OF SAID CHAMBERS, PORTS IN SAID CHAMBERS AT POINTS SPACED FROM RESPECTIVE VALVES AND AN AIR DOME MEMBER IN AT LEAST ONE OF SAID CHAMBERS INTERMEDIATE THE RESPECTIVE PORT AND THE RESPECTIVE VALVE, SAID AIR DOME MEMBER BEING SECURED IN SAID CHAMBER AND MEANS WHEREBY SAID MEMBER IS SPACED RADIALLY FROM WALLS OF SAID CHAMBER TO PERMIT FUEL TO FLOW TO THE RESPECTIVE VALVE BETWEEN SAID WALLS AND SAID MEMBER. 